Beta-gallia-rutile (BGR) intergrowths possess one-dimensional tunnels that are suitable hosts for small-to-medium cations, thereby making them potential candidates for ion conductors, ion separators, battery electrodes, and chemical sensors. The BGR intergrowths are a series of homologous compounds expressed generically as Ga4Mn-4O2n-2, where n is an integer; and M is a tetravalent cation that forms a rutile-type oxide. In an attempt to identify materials with high tunnel densities and higher contents of a reducible M4+ cation, we are mapping the compositional stability regions of intergrowths expressed as Ga4–4xIn4xSn(n-4)(1-y)Ti(n-4)yO2n-2 where n = 6, 7 and 9 and 0.15 < x < 0.30 and 0 < y < 1.0. Polycrystalline samples were prepared by solid-state reaction at 1250 – 1400 °C and characterized by X-ray diffraction. Factors that affect phase stability are discussed.